Investigators will study cervical spinal cord chemical concentrations and cervical spinal cord and brain microstructure in amyotrophic lateral sclerosis(ALS) patients who have had a stem cell transplant compared to ALS patients who have not had a stem cell transplant. Investigators intend to determine cervical spinal cord chemical concentrations and cervical spinal cord and brain microstructure in amyotrophic lateral sclerosis(ALS) patients who have had a stem cell transplant and compare these to corresponding measures in amyotrophic lateral sclerosis(ALS) patients who have not had a stem cell transplant.